The human Rho guanine nucleotide exchange factor (RGNEF) is a homolog of mouse p190RhoGEF that has been recently identified as a novel human NFL mRNA binding protein in Amyotrophic Lateral Sclerosis (ALS) affected spinal cords. ALS - also known as Charcot's Disease, Lou Gehrig's disease and Motor Neuron Disease – is a rapidly progressive, and fatal, neuromuscular disease characterized by the gradual degeneration and death of motor neurons in the brain and spinal cord, which lead to progressive paralysis of the muscles.